Patients with a broad range of neoplastic diseases will be entered upon treatment protocols developed by Cancer and Leukemia Group. These protocols, employed under carefully defined conditions, seek to extend our knowledge as to the best use of established drugs and new chemotherapeutic agents and other modalities of treatment in the management of malignant diseases. Individuals from this institution are presently taking part in protocol design and evaluation in addition to monitoring results of ongoing treatment protocols. The staff of this institution has been particularly interested in the development of new treatment programs for multiple myeloma and small cell carcinoma of the lung. Concepts of immunotherapy developed within this institution have been applied to group wide studies in the past, and a wide variety of pilot studies are presently underway, for knowledge derived from these studies may eventually be extended to group wide protocols. Within the past two years, considerable efforts have been made at this institution in studying the radiosensitizing effects of cisdichlorodiammineplatinum (II) (cis-PDD) and in the identification and quantitation of steroid receptors in cells removed from patients with acute myeloblastic leukemia and the effects of steroids on the metabolism of these cells.